1. Field of Invention
The present invention relates to a liquid crystal display and an electronic device. More particularly, the invention relates to a configuration of a transflective liquid crystal display.
2. Description of Related Art
The related art includes reflective liquid crystal displays that can be used for various portable electronic devices and other devices because such displays do not include a light source, such as a backlight, and therefore have low power consumption. However, in the reflective liquid crystal displays, outside light, such as natural light or artificial light, is used to display an image, and therefore a problem arises that a displayed image cannot be visually identified under dark conditions. Therefore, the related art includes the following display: a liquid crystal display in which outside light is used under light conditions in common with ordinary reflective liquid crystal displays, and an internal light source is used to display an image in a visible manner under dark conditions. That is, this liquid crystal display operates in both reflective and transmissive modes and switches between reflective and transmissive modes depending on the brightness of the environment, whereby a clear image can be displayed under dark conditions while power consumption is saved. This type of liquid crystal display is hereinafter referred to as a “transflective liquid crystal display”. A transflective film used for such a transflective liquid crystal display includes, for example, a related art metal film having openings through which light passes and a film, so called a half mirror, having a thickness adjusted such that one part of incident light is reflected and the other part is transmitted.
The related art includes the following splitter: a polarized beam splitter (hereinafter “PBS”) that includes a prism and a multilayer dielectric film, disposed thereon, functioning as a semi-transmissive film and has a function of dividing incident light into two linearly polarized beams having polarization directions orthogonal to each other. The related art includes a PBS array, equipped with a plurality of PBSs arranged in an array, functioning as a reflective polarizing film, as disclosed in Japanese Unexamined Patent Application Publication No. 5-19208. Furthermore, the related art includes a liquid crystal display including a liquid crystal panel, a backlight, and such a PBS array disposed therebetween, as disclosed in Japanese Unexamined Patent Application Publication No. 7-64085. According to such a liquid crystal display, light emitted from the backlight is divided into two linearly polarized beams with the PBS array, one is transmitted to the liquid crystal panel, and the other is reflected toward the backlight such that the reflected beam is used together with light emitted from the backlight, thereby achieving high light-utilization efficiency.